TIL

Debugging WoW Addons with SavedVariables

WoW addons run in a sandboxed Lua environment and cannot write arbitrary files to disk. However, they can save data to SavedVariables, which get written when you /reload or log out.

The Workflow

  1. Add a debug SavedVariable to your .toc file: 
    ## SavedVariables: MyAddonDB, MyAddonDebug
  2. Create a function that dumps frame/API info to the SavedVariable: 
    function MyAddon:DumpDebugInfo()
    MyAddonDebug = {
        timestamp = date("%Y-%m-%d %H:%M:%S"),
        -- collect whatever data you need
    }
    print("Debug info saved. Do /reload to write SavedVariables.")
end

  3. Trigger the dump via slash command, then /reload to flush to disk

  4. Read the SavedVariables file from outside the game: 
    WTF/Account/<ACCOUNT>/SavedVariables/MyAddon.lua

Example: Discovering Frame Structure

function MyAddon:InvestigateFrame(frameName)
    local frame = _G[frameName]
    if not frame then return end

    MyAddonDebug = {
        regions = {},
        children = {},
    }

    -- Get regions (textures, fontstrings)
    for i, region in ipairs({frame:GetRegions()}) do
        table.insert(MyAddonDebug.regions, {
            type = region:GetObjectType(),
            name = region:GetName() or "unnamed",
            shown = region:IsShown(),
        })
    end

    -- Get children (frames)
    for i, child in ipairs({frame:GetChildren()}) do
        table.insert(MyAddonDebug.children, {
            type = child:GetObjectType(),
            name = child:GetName() or "unnamed",
            shown = child:IsShown(),
        })
    end
end

Reading Errors with BugSack/BugGrabber

If you have BugSack installed, Lua errors are captured in !BugGrabber.lua:

WTF/Account/<ACCOUNT>/SavedVariables/!BugGrabber.lua

After hitting errors, /reload and read this file for full stacktraces.

Why This Matters

This workflow enables an external tool (like Claude Code) to: